Molded contrast mask for display module

ABSTRACT

A display module comprises a circuit board, a plurality of light-emitting elements coupled to a front surface of the circuit board and arranged in an array configured to produce at least a portion of a display image at the front surface of the circuit board, and a contrast mask directly coupled to the front surface of the circuit board, the contrast mask defining a plurality of windows, with each window surrounding a group of one or more of the plurality of light-emitting elements.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of priority to U.S. ProvisionalPatent Application Ser. No. 62/845,555 entitled “MOLDED CONTRAST MASKFOR DISPLAY MODULES,” filed May 9, 2019, the disclosure of which isincorporated by reference herein in its entirety.

BACKGROUND

Displays comprising a plurality of light-emitting elements are used todisplay one or more of textual, graphical, or video information. In someapplications, such as digital billboards or scoreboards, individualdisplay modules are connected to one or more support structures andoperated collectively to form a larger display. Displays can be operatedin outdoor applications where bright sunlight can occasionally interferewith the appearance of the textual, graphical, or video information.

SUMMARY

The present disclosure describes a display comprising one or moredisplay modules arranged to produce a display image comprising textual,graphical or video information. Each display module includes a contrastmask that is directly coupled to the front surface of a circuit board ofthe display module so as to provide for improved contrast for thedisplay, particular in direct sunlight. In an example, each displaymodule includes a plurality of light-emitting elements arranged ingroups of pixels, wherein a pixel pitch between adjacent pixels is nomore than about 4 millimeters, and in some examples is no more than 2.5millimeters, and the contrast mask is molded directly to the frontsurface of the circuit board to form windows that each surround one ormore pixels of the display module.

BRIEF DESCRIPTION OF THE FIGURES

The drawings illustrate generally, by way of example, but not by way oflimitation, various embodiments discussed in the present document.

FIG. 1 is a partial perspective view of an example display comprising aplurality of individual display modules that are operated in acooperative manner to display information on the light-emitting display.

FIG. 2 is a perspective view of an example display module, which can beused as one of the individual display modules in the example display ofFIG. 1.

FIG. 3 is an elevation view of an example display module that includes acontrast mask molded directly to a front surface of a circuit board ofthe display module.

FIG. 4 is a cross-sectional side view of the example display module ofFIG. 3 taken along line 4-4 in FIG. 3.

FIG. 5 is flow diagram of an example method of forming an exampledisplay module with a contrast mask molded directly to a front surfaceof the display module's circuit board.

FIG. 6 is a close-up elevation view of an example package of a pluralityof light-emitting elements for a display module with a contrast maskdirectly molded to the front surface of a circuit board of the displaymodule.

FIG. 7 is a cross-sectional side view of the example package and theexample contrast mask of FIG. 6 taken along line 7-7 in FIG. 6.

FIGS. 8A, 8B, and 8C are elevation views of example packages oflight-emitting elements having various example configurations.

DETAILED DESCRIPTION

The following detailed description includes references to theaccompanying drawings, which form a part of the detailed description.The drawings show, by way of illustration, specific embodiments in whichthe invention may be practiced. These embodiments, which are alsoreferred to herein as “examples,” are described in enough detail toenable those skilled in the art to practice the invention. The exampleembodiments may be combined, other embodiments may be utilized, orstructural, and logical changes may be made without departing from thescope of the present invention. While the disclosed subject matter willbe described in conjunction with the enumerated claims, it will beunderstood that the exemplified subject matter is not intended to limitthe claims to the disclosed subject matter. The following detaileddescription is, therefore, not to be taken in a limiting sense, and thescope of the present invention is defined by the appended claims andtheir equivalents.

References in the specification to “one embodiment”, “an embodiment,”“an example embodiment,” etc., indicate that the embodiment describedcan include a particular feature, structure, or characteristic, butevery embodiment may not necessarily include the particular feature,structure, or characteristic. Moreover, such phrases are not necessarilyreferring to the same embodiment. Further, when a particular feature,structure, or characteristic is described in connection with anembodiment, it is submitted that it is within the knowledge of oneskilled in the art to affect such feature, structure, or characteristicin connection with other embodiments whether or not explicitlydescribed.

Values expressed in a range format should be interpreted in a flexiblemanner to include not only the numerical values explicitly recited asthe limits of the range, but also to include all the individualnumerical values or sub-ranges encompassed within that range as if eachnumerical value and sub-range is explicitly recited. For example, aconcentration range of “about 0.1% to about 5%” should be interpreted toinclude not only the explicitly recited concentration of about 0.1 wt. %to about 5 wt. %, but also the individual concentrations (e.g., 1%, 2%,3%, and 4%) and the sub-ranges (e.g., 0.1% to 0.5%, 1.1% to 2.2%, and3.3% to 4.4%) within the indicated range.

In this document, the terms “a,” “an,” or “the” are used to include oneor more than one unless the context clearly dictates otherwise. The term“or” is used to refer to a nonexclusive “or” unless otherwise indicated.Unless indicated otherwise, the statement “at least one of” whenreferring to a listed group is used to mean one or any combination oftwo or more of the members of the group. For example, the statement “atleast one of A, B, and C” can have the same meaning as “A; B; C; A andB; A and C; B and C; or A, B, and C,” or the statement “at least one ofD, E, F, and G” can have the same meaning as “D; E; F; G; D and E; D andF; D and G; E and F; E and G: F and G; D, E, and F; D, E, and G; D, F,and G; E, F, and G; or D, E, F, and G.” A comma can be used as adelimiter or digit group separator to the left or right of a decimalmark; for example, “0.000,1”” is equivalent to “0.0001.”

Throughout this document, values expressed in a range format should beinterpreted in a flexible manner to include not only the numericalvalues explicitly recited as the limits of the range, but also toinclude all the individual numerical values or sub-ranges encompassedwithin that range as if each numerical value and sub-range is explicitlyrecited. For example, a range of “about 0.1% to about 5%” or “about 0.1%to 5%” should be interpreted to include not just about 0.1% to about 5%,but also the individual values (e.g., 1%, 2%, 3%, and 4%) and thesub-ranges (e.g., 0.1% to 0.5%, 1.1% to 2.2%, 3.3% to 4.4%) within theindicated range. The statement “about X to Y” has the same meaning as“about X to about Y,”” unless indicated otherwise. Likewise, thestatement “about X, Y, or about Z” has the same meaning as “about X,about Y, or about Z,” unless indicated otherwise.

The term “about” as used herein can allow for a degree of variability ina value or range, for example, within 10%, within 5%, within 1%, within0.5%, within 0.1%, within 0.05%, within 0.01%, within 0.005%, or within0.001% of a stated value or of a stated limit of a range, and includesthe exact stated value or range.

The term “direction” used herein can refer to, unless otherwisespecified, to a linear direction for the purposes of describing orcharacterizing a physical location of a particular structure, forexample to describe the physical location of one structure relative toanother structure. In some specific examples, the term “direction” isused to refer to one or more reference directions for the purposes ofdescribing or characterizing relative positioning of one structurerelative to another. For example, a common set of reference directionsthat is well known to those of skill in the art are the directions usedto describe three-dimensional Euclidean space, and in particular thedirections associated with each axis of a three-dimensional Cartesiancoordinate system. As will be appreciated by those having skill in theart, Cartesian coordinates are often used to define positions within athree-dimensional space by defining three imaginary reference axes,typically named the “x-axis,” the “y-axis,” and the “z-axis,” which arepairwise perpendicular. These axes can also be used to define a“direction” associated with each axis, referred to herein as an“x-direction” defined as a linear direction that is parallel to thex-axis (but not necessarily coincident with the x-axis), a “y-direction”defined as a linear direction that is parallel to the y-axis (but notnecessarily coincident with the y-axis), and a “z-direction” defined asa linear direction that is parallel to the z-axis (but not necessarilycoincident with the z-axis).

The term “substantially” as used herein refers to a majority of, ormostly, such as at least about 50%, 60%, 70%, 80%, 90%, 95%, 96%, 97%,98%, 99%, 99.5%, 99.9%, 99.99%, or at least about 99.999% or more, or100%.

In addition, it is to be understood that the phraseology or terminologyemployed herein, and not otherwise defined, is for the purpose ofdescription only and not of limitation. Any use of section headings isintended to aid reading of the document and is not to be interpreted aslimiting, and information that is relevant to a section heading mayoccur within or outside of that particular section. All publications,patents, and patent documents referred to in this document areincorporated by reference herein in their entirety, as thoughindividually incorporated by reference. In the event of inconsistentusages between this document and those documents so incorporated byreference, the usage in the incorporated reference should be consideredsupplementary to that of this document; for irreconcilableinconsistencies, the usage in this document controls.

In the methods described herein, the acts can be carried out in anyorder without departing from the principles of the disclosed method,except when a temporal or operational sequence is explicitly recited.Furthermore, specified acts can be carried out concurrently unlessexplicit language recites that they be carried out separately. Forexample, a recited act of doing X and a recited act of doing Y can beconducted simultaneously within a single operation, and the resultingprocess will fall within the literal scope of the process. Recitation ina claim to the effect that first a step is performed, then several othersteps are subsequently performed, shall be taken to mean that the firststep is performed before any of the other steps, but the other steps canbe performed in any suitable sequence, unless a sequence is furtherrecited within the other steps. For example, claim elements that recite“Step A, Step B, Step C, Step D, and Step E” shall be construed to meanstep A is carried out first and steps B, C, D, and E can be carried outin any sequence between steps A and E, and that the sequence still fallswithin the literal scope of the claimed process. A given step or sub-setof steps may also be repeated.

Electronic Display

FIG. 1 shows an example of an information display 10 (also referred tosimply as “display 10”) that is configured to display one or more ofgraphics, video, or text. For the sake of brevity, this disclosure willrefer to the information that is presented on the display 10 as a“display image.” However, those of skill in the art will appreciate thatthe display 10 is not limited solely to a graphical image or a staticimage, and will understand any recitation of a “display image” asreferring to one or any combination of display graphical information(e.g., an image intended to represent a real or imaginary object ofconcept), video information (e.g., a series of two or more imagesdisplayed in succession so as to imitate motion), or textual information(e.g., letters, numbers, symbols, or other characters intended torepresent language or other communication) being presented on thedisplay 10 during the same period of time. The display 10 includes oneor more individual display modules 12 mounted to one or more supports,such as a support chassis 14 (also referred to as a frame 14).

In some examples, the display 10 described herein is configured forrelatively large-scale display of one or more display images to arelatively large number of viewers, such as a video display for a largevenue such as a sports stadium or arena or a large music concert arenaor venue, or a display on a digital or video billboard display. In anexample, either a display module 12 or the support chassis 14, or both,includes a mounting structure or apparatus at one or more locationsrelative each display module 12 to mount or couple each display module12 to the support chassis 14, such as one or more latches. FIG. 1 showsone of the display modules 12 being in a tilted position relative to thesupport chassis 14, which can occur when that display module 12 is inthe process of being mounted to, or dismounted from, the support chassis14. The other display modules 12 in the display 10 have already beenmounted to the support chassis 14, such as with one or more latches orother mounting hardware. In examples wherein the display 10 is formedfrom a plurality of the display modules 12, the plurality of displaymodules 12 operate together so that the overall display 10 appears as asingle, larger display surface 16. The display 10 can be configured todisplay the display image on the display surface 16. A plurality oflight-emitting elements 18 are mounted to the display surface 16. Forexample, each of light-emitting elements 18 can be mounted to one ormore mounting structures of a corresponding display module 12, such asone or more of a circuit board, potting, or a module frame. In such anexample, the light-emitting elements 18 are controlled in a cooperativemanner so that the display 10 shows the display image on the displaysurface 16.

The light-emitting elements 18 can be any type of light-emittingtechnology known or yet to be discovered for the emission of light froma small area, e.g., so that from a distance the light from anyparticular light-emitting element 18 will appear to be a small point oflight. As described in more detail below, in some examples eachlight-emitting element 18 is small enough such that it can cooperatewith one or more additional light-emitting elements 18 in an area smallenough so as to appear as an individual pixel, e.g., that will appear asa single discrete point of light, which can itself cooperate with aplurality of other pixels to form a visual representation of the displayimage being displayed on the display surface 16. In particular, thelight-emitting elements 18 can be of any type of light-emittingtechnology that is or can be used for the display of visual information,such as video information, graphical information, or textualinformation. At the time of filing of the present application,light-emitting diodes (LEDs) are one of the most common light-emittingtechnologies in use for video or graphical displays of the typedescribed herein. As such, for the sake of brevity, the remainder of thepresent disclosure will refer to light-emitting elements that can beused in a display, including the light-emitting elements 18 shown in thefigures, will be referred to as LEDs 18. Those of skill in the art willappreciate, however, that any time the present disclosure uses the term“light-emitting element,” “light-emitting diode” or “LED,” it isreferring not only to LEDs, as they are understood at the time offiling, but also refers to other light-emitting technologies anddevices, including, but not limited to, liquid crystal display devices(LCDs), organic light-emitting diodes (OLEDs), light-emitting transistordevices (LETs), organic light-emitting transistors (OLETs),surface-conduction electron-emitter display devices (SEDs),field-emission display devices (FEDs), quantum dot display devices suchas quantum dot liquid crystal display devices (QD-LCDs) or quantum dotlight-emitting diode display devices (QD-LEDs), ferro-liquid displaydevices (FLDs), and thick-film dielectric electroluminescent devices(TDELs).

FIG. 2 is a perspective view of an example display module 12 that can beused in the display 10 of FIG. 1. The display module 12 includes a frontface 20 configured to provide for a display visual content. A pluralityof the LEDs 18 are positioned on the front face 20 and the LEDs 18 canbe operated in such a way that the display module 12 will display atleast a portion of the display image (e.g., at least a portion of theoverall video, graphic, or text that is to be shown on the display 10 asthe display image). The front face 20 of the display module 12 isaligned and oriented relative to front faces 20 of one or moreadjacently positioned display modules 12 so that the front faces 20combine and cooperatively form the overall display surface 16 of thefull display 10 (shown in FIG. 1). The plurality of display modules 12are operated together in such a way as to display the display image in acohesive manner so that the entire display 10 appears to a viewer as asingle display that is larger than the individual display modules 12.

In an example, the LEDs 18 are arranged into an array of pixels 22 (bestseen in FIG. 2). Each pixel 22 includes one or more LEDs 18 groupedtogether in close proximity. The proximity of the pixels 22 allows thedisplay 10 to be operated in such a way that they will appear to aviewer of the display 10 to form recognizable shapes, such as letters ornumbers to display textual information or recognizable geometries todisplay graphical or video information. In some examples, the pluralityof LEDs 18 include a plurality of different-colored LEDs 18 in each ofthe pixels 22 that can be cooperatively operated to display what appearsto be a spectrum of different colors for the viewer of the display 10,e.g., using an additive color method. In a common example, each pixel 22includes a red LED 18, a green LED 18, and a blue LED 18, wherein thered, green, and blue LEDs of each pixel 22 cooperate to provideessentially the entire color spectrum that is visible to humans based onwhether one, two, or all three of the LEDs 18 in a pixel 22 are lit, andat what intensities. Those of skill in the art will appreciate thatother combinations of specific colors of LEDs 18 can be selected foreach pixel 22, depending on the specific colors and performance desiredfor the display 10. The display 10 can also provide a black or emptylooking surface over a portion of the display, when desired, bydeactivating or turning off the LEDs in a designated area of pixels 22.

In the example shown in FIG. 2, each pixel 22 includes a plurality ofLEDs 18 arranged in a specified pixel shape. The example of FIG. 2 showsa linear or substantially linear pixel shape comprising three LEDs 18(e.g., corresponding to the red LED 18, green LED 18, and blue LED 18discussed above) that are aligned or substantially aligned in a commondirection, such as in the vertically aligned pixel shape of the pixels22 shown in FIG. 2. Those of skill in the art will appreciate that pixelshapes other than a vertical or substantially vertical pixel 22 can beused, including, but not limited to: a linear or substantially linearpixel oriented in a direction other than vertical (e.g., a horizontal orsubstantially horizontal pixel shape or a diagonal linear pixel shape),or geometrical pixel shapes with one or more LEDs at each vertex of aspecified geometrical shape (such as a triangular pixel formed fromthree LEDs, a quadrilateral pixel formed from four LEDs, and so on).

In an example, the pixels 22 are arranged in a grid-like array, such asa grid including a specified number of rows and a specified number ofcolumns of the pixels 22 that are spaced by a specified spacingdistance. In some examples, the specified spacing between adjacentpixels 22, also referred to as the “pixel spacing” or the “pixel pitch,”is uniform or substantially uniform throughout the entirety of thedisplay surface 16. In some examples, each row of pixels 22 is spacedfrom adjacent rows on either side by the specified uniform orsubstantially uniform pixel pitch, and similarly each column of pixels22 is spaced from adjacent columns on either side by the same specifieduniform or substantially uniform pixel pitch. Uniform or substantiallyuniform pixel spacing provides for display images with geometries thatappear to be solid or uniform shapes for a view of the display 10 andcan add to the realism of the display image for the viewer and/orfidelity to the desired content to be displayed on the display 10.

The size of the pixel pitch can be selected depending on the size of thedisplay 10 (e.g., a total surface area of the display surface 16, whichcan also be described according to the length of the display surface 16along one or more defined directions, such as a width of the display 10in a first direction, such as a horizontal or substantially horizontaldirection, and a height of the display in a second direction that isgenerally perpendicular to the first direction, such as a verticaldirection), the distance that is expected between the display 10 andviewers of the display 10, and the specified resolution selected for thedisplay 10. As used herein, the term “resolution” refers to the totalnumber of pixels 22 in the display in one or more of the defineddirections, such as in the first direction (e.g., the horizontal orsubstantially horizontal direction corresponding to the width of thedisplay 10) or the second direction (e.g., the vertical or substantiallyvertical direction corresponding to the height of the display 10), orboth. “Resolution” can also be defined in terms of a pixel density, suchas a specified number of pixels per unit of area or per unit of lengthin one or more of the defined directions. Those of skill in the art willappreciate that the pixel density of a display is inversely related tothe pixel pitch—e.g., as the pixel pitch gets smaller and smaller, thepixel density gets larger and larger.

In some examples, described in more detail below, the LEDs 18 areprovided in the form of a plurality of discrete electronic devices,sometimes referred to as LED packages. In an example, each LED packageincludes one or more LEDs 18 and at least a portion of the supportingelectronics for lighting and controlling the one or more LEDs 18.Depending on the size of the specified pixel pitch, each LED package canbe configured for an individual LED 18 (in which case a pixel 22comprising a plurality of the LEDs 18 would be made up of an equalnumber of LED packages) or each pixel 22 can be made up of its own LEDpackage (in which case the LED package would include all of the LEDs 18that are part of the pixel 22 as well as supporting electronics forthose LEDs 18).

In an example, the display 10 is controlled with control software and/orone or more hardware controllers, so that the display image is brokendown into coordinates. Each coordinate can correspond to a specificpixel location within the overall display 10, and the control softwareand/or the one or more hardware controllers can operate each pixelaccording to a program that specifies a condition for each coordinatewithin the display 10 and controls each of the pixels 22 so that it willappear to emit light that meets the condition specified. For example, ifthe display 10 is displaying a series of display images (either toappear as static images, or to appear as a moving video), the controlsoftware and/or the one or more hardware controllers can be fed the datacorresponding to the series of display images, and the control softwareand/or the one or more hardware controllers can break the series ofdisplay images down into conditions for each pixel 22—such as the timewithin the series of messages, the color hue that a pixel 22 is todisplay at that time, the color saturation that the pixel 22 is todisplay at that time, and the intensity of the pixel 22 at that time.The control software and/or the one or more hardware controllers canalso convert the information regarding color (e.g., hue and saturation)and intensity into specific operating parameters for each LED 18 in aparticular pixel 22, such as the power that will be supplied to the redLED 18, the blue LED 18, and the green LED 18 in that pixel 22 and forhow long in order to achieve the specified color and intensity at thespecified time. The control software and/or the one or more hardwarecontrollers can then send control signals to the pixels 22 or toindividual LEDs 18, e.g., to the LED package or packages associated witheach pixel 22, to operate each pixel 22 according to the specifiedseries of display images. Although a grid or grid-like array of pixelsas summarized above is common, the display 10 described herein can useother arrangements of the LEDs 18 or other systems for addressing theLEDs 18 can be used without varying from the scope of the presentdisclosure.

Contrast Mask

In an example, the display 10 includes one or more structures configuredto enhance contrast between light being emitted from the LEDs 18 and theappearance of dark or black in the display image, also referred tosimply as “contrast-enhancing structures,” in order to improve one ormore of visibility, readability, or overall appearance of the displayimage. Contrast-enhancing structures can be made from a material that isdark, such as a black material, or can be died or otherwise colored tobe a dark color, such as black, to cover up or interference with areasaround one or more LED packages associated with each pixel 22 that mightotherwise reflect or distort light being emitted from the pixels 22. Theone or more contrast-enhancing structures can, for example, reducereflection or distortion of light emitted from the pixels 22 to reducethe occurrence of a halo effect around individual pixels 22 or LEDs 18,e.g., by minimizing or eliminating the occurrence of the halo effect.The one or more contrast-enhancing structures can also improveviewability of the display 10 and the display image in produces when thedisplay 10 is exposed to bright and direct light onto the displaysurface 16, such as when sunlight shines on the display 10. For example,the one or more contrast-enhancing structures can also shade one or morecorresponding LEDs 18 from direct sunlight or other bright lighting,which can prevent or reduce glare off the LEDs 18, which is known tointerfere with projection of a true color from the LEDs 18.

FIGS. 1 and 2 show an example of one or more contrast-enhancingstructures in the form of a contrast mask 24, also referred to as a facecover 24 that is placed onto the front face 20 of each display module12. In addition to enhancing contrast for the LEDs 18, the contrast mask24 can also provide protection for one or more of the LEDs 18, thedisplay surface 16, and the electrical components of the display modules12.

As discussed above, the spacing between adjacent pixels 22 on thedisplay 10, also referred to as the “pixel pitch,” is inversely relatedto the pixel density and overall resolution of the display 10. The trendin the industry of display modules is toward smaller and smaller pixelpitches to provide for the display of sharper and sharper display imagesthat include smaller and smaller image features, much like similartrends in television technology (e.g., from standard definition to 720phigh definition to 1080p high definition to ultra-high definitiontelevision such as 4K UHD and 8K UHD) and digital camera technology(e.g., to higher and higher sensor resolutions). Therefore, customers oflarge-scale LED displays provide a great deal of demand for smaller andsmaller pixel pitches and the LED display module industry has a strongmotivation to make displays with smaller and smaller pixel pitches.

As will be appreciated, the smallest sizes that are possible for thepixel pitch depend on the technology available in several technicalfields. For example, the size of the pixel pitch depends to a largedegree on how small the individual components can be made (e.g., theLEDs 18 and the LED packages) while still providing for desiredspecifications (such as brightness, color density, color range, powerusage, typical component lifetime, and expected component reliability)and how closely the components can be spaced and still operated at thosedesired specifications (e.g., whether there are manufacturing techniquesthat can mount the components close enough together on a circuit boardto achieve a smaller pixel pitch). Through advancements in thesetechnologies, the smallest pixel pitch that is reliably achievable forlarge-scale LED displays has been reduced from about 4 millimeters(“mm”) in 2012 to 2.5 mm or less in 2018.

While advancement in LED technology, supporting electronics technology,and manufacturing techniques have made smaller and smaller pixel pitchesreliably possible, this shrinking of pixel pitch distances has led toother challenges. For example, very small pixel pitches, e.g., thosesmaller than about 4 mm and particularly those that are 2.5 mm or less,can make it difficult to fit contrast-enhancing structures betweenadjacent pixels 22, e.g., between the LED packages that form the pixels22. It has also been difficult to reliably secure the contrast-enhancingstructures to the display module 12. When the pixel pitch is larger,such as 5 mm or greater, then contrast-enhancing structures typicallyhave been manufactured separately from the display module, such as bymolding a plastic face cover or louver structure that is then snappedonto or otherwise secured to the display module. This type of separatelyformed contrast-enhancing structure is also referred to as a “secondarypart” or a “secondary contrast structure.” However, with smaller pixelpitch spacing (e.g., 4 mm or less, and in particular 2.5 mm or less), itbecomes difficult or impossible to make secondary contrast structures byconventional manufacturing methods (e.g., injection molding or othermolding techniques) because the sizes of some features of such asecondary contrast structure are simply too small to be made reliablyand predictably via conventional methods.

The present disclosure describes a contrast-enhancing structure thatavoids this problem with secondary contrast structures by making one ormore contrast-enhancing structures that are molded directly onto thedisplay module, such as by being molded directly onto a circuit boardonto which the LEDs or LED packages are mounted. The inventors of thesubject matter of the present disclosure have discovered that formingone or more contrast-enhancing structures by molding, and inparticularly by molding directly onto a circuit board or otherelectronics-supporting structure can allow the one or morecontrast-enhancing structures to be made small enough to fit betweenLEDs or LED packages that are mounted to the circuit board so thatadverse effects associated with the light being emitted from the LEDs,such as the distortion or glare described above, can be minimized evenon a display with small or very small pixel pitches, such as 4 mm orless, and in particular 2.5 mm or less.

FIG. 3 shows a top view of a portion of an example display module 30that incorporates the concepts of a directly molded contrast-enhancingstructure or structures summarized above. FIG. 4 shows a cross-sectionalside view of the display module 30 shown in FIG. 3. As shown in FIGS. 3and 4, the display module 30 includes a plurality of packages 32arranged in an array, such as a linear array shown in FIG. 3. Eachpackage 32 includes one or more light-emitting elements, such as one ormore LEDs (not shown), and can also include at least a portion of thesupporting electronics for powering and controlling the one or morelight-emitting elements, such as drivers, control circuitry, and thelike. As described above, at the time of filing, LEDs were the mostcommon type of light-emitting technology used for light-emittingelements in this type of display module and, therefore, the packages 32will be referred to as “LED packages 32” for the sake of clarity,although the packages 32 are not limited to LED technology. In this way,FIGS. 3 and 4 can be thought of as showing a close-up view of a portionof a larger display surface of the display module 30 (similar to thedisplay surface 16 for the display 10 of FIGS. 1 and 2), for example aportion of one row of pixels that make up the display surface.

In an example, each LED package 32 includes all of the LEDs that make upa single pixel within the display module 30, similar to the pixels 22 ofLEDs 18 described above for the display 10 in FIGS. 1 and 2. Forexample, if the display module 30 is designed so that each pixelcomprises one red LED, one green LED, and one blue LED, than in anexample each LED package 32 includes three (a red LED, a green LED, anda blue LED). Each LED package 32 can also include at least a portion ofthe supporting electronics that provide for the emission of light fromthe LEDs on the LED package 32, such as LED drivers or other electroniccomponents to allow the red LED to emit red light, the green LED to emitgreen light, and the blue LED to emit blue light. The LED packages 32are electrically mounted to an electronics-support structure 34, such asa printed circuit board 34 (referred to simply as “the circuit board 34”hereinafter for brevity). The circuit board 34 can also include otherstructures that have been pre-formed or pre-mounted onto the surface ofthe circuit board 34 or pre-formed within or through the circuit board34, for example supporting electronics for the LED packages 32 orconducting traces for transmission of signals or power to or from theLED packages 32 (not shown in FIGS. 3 and 4).

In examples where each LED package 32 corresponds to a pixel of thedisplay module 30 (e.g., with each LED package 32 including a red LED, agreen LED and a blue LED), than the LED packages 32 are mounted to thecircuit board 34 at specified positions on the circuit board 34corresponding to the desired spacing between the pixels of the displaymodule 30. In other words, the LED packages 32 are mounted to thecircuit board 34 so that the LED packages 32 are spaced by a specifiedpixel pitch, designated as “PP” in FIGS. 3 and 4.

In the example shown in FIGS. 3 and 4, each LED package 32 iselectrically coupled to the circuit board 34 via one or more wires 36 orother electrical connection that are each electrically connected to acorresponding connection pad 38 on the circuit board 34 and acorresponding connection pad 40 on the LED package 32. Each connectionpad 38 on the circuit board 34 can be electrically connected tosupporting electronics, such as a controller, via one or moreelectrically connection, such as electrical traces on the circuit board34 (not shown). Each connection pad 40 can be electrically connected toone or more electronic devices in the LED package 32, such as one ormore of the LEDs in the LED package 32 or supporting electronics for theLEDs. Each LED package 32 can also be electrically connected to thecircuit board 34 via a surface mount connection in place of or inaddition to the one or more wires 36, such as a back side of the LEDpackage 32 that is electrically mounted to a corresponding surface-mountconnection pad on a front surface 44 of the circuit board 34 (notshown).

The display module 30 also includes a contrast mask 42 that is directlycoupled to the circuit board 34 (or to a coating or film on the surfaceof the circuit board 34), for example by being coupled to at least thefront surface 44 of the circuit board 34. As used herein, the terms“coupled directly to,” “direct coupling,” and the like, when referringto a contrast mask like the example contrast mask 42 shown in FIGS. 3-5,means that at least a portion of one surface of the contrast mask isphysically attached to at least a portion of one or more surfaces of thecircuit board 34. Direct coupling between the contrast mask 42 and thecircuit board 34 can refer to the material or materials of the contrastmask 42 being bonded (either chemically or physically) to the materialor materials of the circuit board 34 at the surface of the directcoupling (e.g., wherein the contrast mask 42 is in physical contact withthe circuit board 34, as shown in FIGS. 3-5), or it can refer to thematerial or materials of the contrast mask 42 being adhered to thesurface of the circuit board 34, such as with an adhesive material, orto the material or materials of the contrast mask 42 being adhered to acoating or film on the surface of the circuit board 34.

In an example, the contrast mask 42 is molded onto at least the frontsurface 44 of the circuit board 34, for example by way of a moldingprocess wherein a contrast-mask material is molded onto at least thefront surface 44 in a specified geometry corresponding to one or moredesired contrast-enhancing structures for the contrast mask 42, such asin the example described in more detail below with respect to FIG. 5. Inthe example shown in FIGS. 3 and 4, the contrast mask 42 has been moldedto form a plurality of windows 46 in or through the contrast mask 42through which the LED packages 32 and/or LED pixels and, in someexamples, a portion of the circuit board 34, are exposed in a frontfacing direction. In this way, the plurality of windows 46 allows atleast a specified portion of the light that is generated by the LEDs ofthe LED packages 32 to be emitted out from the LED packages 32 toprovide the display image on a display surface formed from the displaymodule 30 (possibly in conjunction and coordination with one or moreother display modules positioned in proximity to the display module 30,similar to that which is described above with respect to the display 10of FIGS. 1 and 2). Each window 46 provides a path for the emission oflight from one or one or more LED packages 32 and/or to one or morepixels on the display module 30.

As used herein, the term “window” can refer to an opening that passesthrough the entirety of the contrast mask 42, e.g., so that a portion ofthe front surface 44 of the circuit board 34 is exposed (as shown in theexample of FIGS. 3 and 4), or can refer to an opening where the contrastmask 42 comes into contact with the LEDs or LED packages 32 but wherethere is still a path for the light from the LEDs to be emitted forwardfrom the display module 30. In other words, the “window” need not passthrough the entirety of the contrast mask 42 so long as the specifiedportion of light generated by the LEDs is emitted forward from the LEDpackages 32 to provide the display image.

In the example shown in FIGS. 3 and 4, there is one window 46 in orthrough the contrast mask 42 corresponding to each individual LEDpackage 32 or pixel of LEDs on the display module 30. The formation ofthe windows 46 in or through the contrast mask 42 results in theformation of internal walls 48 of the material of the contrast mask 42that each separate a pair of adjacent LED packages 32, best seen in FIG.4. Each internal wall 48 also partially defines a peripheral edge foreach of the windows 46 that the internal wall 48 is between. Theformation of the windows 46 also results in an external wall 50 betweeneach outermost LED package 32 (e.g., the left-most and right-most LEDpackages 32 in FIGS. 3 and 4) and an outer edge 52 of the display module30, wherein each external wall 50 separates the outermost LED package 32from the outer edge 52 and also partially defines the peripheral edge ofthe window 46 around the outermost LED package 32.

As noted above, the example display module 30 shown in FIG. 3 onlyincludes a single row of LED packages 32 to simply the illustration andthe identification of structures. However, as noted above, the displaymodule 30 of the present disclosure is not limited to a single row ofLED packages 32, and could include an array of LED packages 32 (e.g.,with a plurality of rows of LED packages 32 forming a grid or grid-likearray of rows and columns). In examples where the display module 30includes more than one row of LED packages 32, the contrast mask 42 caninclude not only the internal walls 48 that separate an LED package 32from an adjacent LED package 32 in the same row (i.e., in theleft-to-right extending row of FIG. 3), but can also include similarinternal walls that separate an LED package 32 from an adjacent LEDpackage 32 in the same column (i.e., in a direction that is generallyperpendicular to the direction of the rows, such as in an up-and-downdirection in FIG. 3). Similarly, in examples where the display module 30includes more than one row of LED packages 32, the contrast mask 42 caninclude an external wall 50 or a series of external walls 50 that extendaround the entire periphery of the contrast mask 42 and correspond onlyto the lateral outermost LED packages 32 of the display module 30 (e.g.,along the left-most, right-most, top-most, and bottom-most edges 52 ofthe display module 30).

As described in more detail below with respect to the examples shown inFIGS. 6-8, the contrast mask 42 is designed so that the windows 46 canbe as small as possible while still allowing a specified amount of lightto be emitted from the LED package 32 or packages 32 corresponding toeach window 46. In other words, the size of the openings of the windows46 is preferably as close as possible to the size of an individual LEDpackage 32. The size of the openings of the windows 46 is preferably assmall as possible so that the material of the contrast mask 42 covers asmuch of the circuit board 34 as possible in order to maximize thecontrast-enhancing effect of the contrast mask 42. In this way, in someexamples the contrast mask 42 covers substantially all of a surface areaof the front surface 44 of the circuit board 34 except for the smallsurface area exposed by the windows 46. However, as described above,there is substantial market pressure for a narrow pixel pitch PP, e.g.,a pixel pitch PP of 4 mm or less, and preferably of 2.5 mm or less. Whenthe spacing between adjacent LED packages 32 is this small, there isvery little surface area on the front surface 44 of the circuit board 34dedicated to each LED package 32. It can be very difficult to fit all ofthe structures of the display module 30 onto this limited surfacearea—including the LED packages 32 themselves, structures for electricalconnection between the LED packages 32 and the circuit board 34, e.g.,the wires 36 and the connection pads 38, and the structure of thecontrast mask 42, e.g., the internal walls 48 and the external walls 50,as well as any other supporting electronics for the LED packages 32.

FIG. 5 is a flow diagram of an example method 100 of manufacturing adisplay module having a contrast mask molded directly to the circuitboard or another electronics-supporting structure, for example, thecontrast mask 42 molded to the circuit board 34 of the display module 30shown in FIGS. 3 and 4. Each set of drawings in FIG. 5 shows a top viewand a cross-sectional side view of the structure at a particular stageof the process.

In an example, the method 100 includes providing or receiving anelectronics-mounting structure, such as the circuit board 34(represented by the top two structures in FIG. 5). In an example, thecircuit board 34 that is provided or received can include a main circuitboard body, and one or more electrical-connecting structures such as theconnection pads 38, that can be pre-formed on the circuit board 34before the subsequent processing steps described below. The circuitboard 34 can also include one or more connection pathways (not shown) toelectrically connect the one or more connection pads 38 to one or moreother structures or devices (not shown) to enable operation of the LEDpackages 32

Next, the method 100 can include, at step 102, molding a moldablematerial onto a front surface 44 of the circuit board 34 in order toform a contrast mask 42. In an example, the moldable material comprisesa moldable polymeric material, such as an elastomeric polymer or athermoplastic polymer. The moldable material that is used to form thecontrast mask 42 can comprise any material that will reliably bond oradhere to the circuit board 34 (e.g., onto the front surface 44 of thecircuit board 34), and can be selected to have one or more specifiedproperties once the moldable material is formed into and sets as thecontrast mask 42. Examples of specified material properties include, butare not limited to: a specified hardness when set; a specifiedglass-transition temperature; a specified compressibility; a specifiedimpact strength; and a specified coefficient of thermal expansion(“CTE”), such as a CTE that matches or substantially matches the CTE ofthe circuit board 34 (within a specified threshold) so that the circuitboard 34 and the contrast mask 42 will expand and contract at the sameor substantially the same rate as the display module 30 experienceschanges in temperature during use.

Examples of the moldable material that can be applied by the step ofcontrast mask molding 102 include, but are not limited to: anepoxy-based compound such as EME-G770SF epoxy sold by Sumitomo Bakelite;a silicone-based compound such as OE-6650 silicone encapsulant sold byDow Corning, or a black carbon compounds such as MONARCH 800 CarbonBlack sold by Cabot Corp.

The step of contrast mask molding 102 provides a coated circuit board54, wherein at least a portion of the front surface 44 of the circuitboard 34 has been coated with the moldable material to form the contrastmask 42. In an example, the step of contrast mask molding 102 includesshaping the moldable material to form specified features of the contrastmask 42, including windows 46 (described above), so that the featureshave a specified geometry, including specified dimensions and sizes(including, but not limited to, those described with respect to theexamples described in FIGS. 6-8).

Any manufacturing technique that can produce the contrast mask 42 withthe specified features and specified geometries can be used for the stepof the contrast mask molding 102. A non-limiting example of a moldingtechnology that has been found to be useful when the display module 30is desired to have a narrow pixel pitch PP, e.g., about 4 mm or less,preferably about 2.5 mm or less, is film-assisted molding technology, or“FAM.” FAM has been found to be useful in forming the structures of thecontrast mask 42 on the small scale that is necessary for a narrow pixelpitch PP (e.g., of 4 mm or less, preferably about 2.5 mm or less) duringthe molding step 102.

In an example, FAM of the contrast mask 42 can include providing orreceiving a mold having a mold cavity with an inner surface geometrythat corresponds to the desired outer geometry of the contrast mask 42(e.g., the inner surfaces of the mold cavity are a reverse-image versionof the outer surfaces of the contrast mask 42). Next, a thin film lineris placed into the mold against the inner surfaces of the mold cavity.The thin film liner is heated to at least partially melt or soften thethin film liner and a vacuum is applied to the at least partially meltedor softened thin film liner to suck the thin film liner tightly onto theinner surfaces of the mold cavity. Then, the circuit board 34 is placedin the mold cavity at a specified position relative to the lined innersurfaces of the mold cavity and the mold cavity is closed. A liquid orsoftened form of the moldable material that will form the contrast mask42 is then injected into the mold cavity so that the moldable materialcan flow over the circuit board 34 and within the free space within themold cavity to form the specified geometry of the contrast mask 42. Theliquid or softened form of the moldable material is injected withsufficient velocity and force so that it will flow into all the freespaces within the mold cavity, e.g., so that there is little to noundesired unfilled space within the mold cavity. In some examples, theinjection of the moldable material can be vacuum assisted, e.g., with avacuum applied to the mold cavity so that moldable material will morereadily fill the open space within the mold cavity. Application of thevacuum can also assist in the extraction of air bubbles or other gasthat may be trapped in the liquid or softened moldable material tominimize or eliminate the formation of small voids in the final contrastmask 42.

After the liquid or softened moldable material has been sufficientlyinjected into the mold cavity, the moldable material is either activelyset or cured or is allowed to passively set or cure (e.g., to solidify)into the solidified contrast mask 42. In an example, additional heat orpressure, or both, can be applied to the mold to drive solidification ofthe moldable material into the solid material of the contrast mask 42and to provide for more uniform and controllable curing of the materialinto the solid contrast mask 42. In examples where a vacuum is appliedto the mold cavity to provide for evacuation of trapped air or othergasses from the liquid or softened moldable material, as describedabove, in some examples the vacuum can continue to be applied to themold cavity while the material solidifies to continue to evacuatetrapped air and other gasses and to minimize or prevent the possibilityof gas diffusing into the moldable material during the curing process.After the moldable material has cured to a specified solidificationvalue, e.g., to a desired hardness within a specified threshold, thenthe mold cavity is opened and the now coated circuit board 54 with themolded contrast mask 42 is removed from the mold cavity. In FAM methods,the used thin film liner can be removed from the inner surfaces of themold cavity and can be replaced by a fresh thin film liner, which isplaced into the mold cavity, heated, and sucked onto the inner surfacesof the mold cavity for the coating of a different circuit board 34 withthe moldable material to form another contrast mask 42.

The method 100 includes, at step 104, electrically mounting a pluralityof LEDs to the circuit board 34, such as within the windows 46 in thecontrast mask 42. In the example shown in FIG. 5, the mounting 104 ofthe LEDs or the LED packages 32 onto the circuit board 34 is performedafter molding 102 the contrast mask 42 onto the circuit board 34. Inexamples where one or more of the LEDs are included as part of an LEDpackage 32, as described above, than step 104 includes electricallymounting a plurality of the LED packages 32 to the circuit board 34,such as by mounting one or more corresponding LED packages 32 in eachwindow 46 in the contrast mask 42. In an example, the mounting of theLEDs or LED packages 32 includes coupling the LED packages 32 to thefront surface 44 of the circuit board 34 (e.g., by welding or adhering abottom surface of each LED package 32 to the front surface 44) andelectrically connecting wires 36 or other electrical connectingstructures between one or more connection pads 38 on the circuit board34 and one or more corresponding connection pads 40 on each LED package32 (best seen in FIGS. 3 and 4). In some examples, the mounting 104 ofthe LEDs or LED packages 32 to the circuit board 34 can be performedbefore the step of molding 102 the contrast mask 42 to the circuit board34 (e.g., the order of steps 102 and 104 can be reversed with respect towhat is shown in FIG. 5).

Optionally, the method 100 can include, at step 106, encapsulating thecoated circuit board 54 and the LED packages 32 with an encapsulationcover 56 to separate and seal an external environment from the circuitboard 34, the LED packages 32, the wires 36 or other electricallyconnections, and any other electronic structures or components. Theencapsulation cover 56 can comprise a transparent or substantiallytransparent material so that the encapsulation cover 56 does notinterfere with the light being emitted from the display module. Inparticular, the encapsulation cover 56 can be useful when the displaymodule 30 is to be used in an exterior environment where the displaymodule 30 will be exposed to weather, and in particular to moisture inthe air or in the form of precipitation. Examples of materials that canbe used to form the encapsulation cover 56 include, but are not limitedto, silicone-based materials or polyurethane-based materials, such asthe silicone electronics encapsulants manufactured by Dow Corning Corp.,Midland, Mich., USA, such as the Dow Corning EE-1184 siliconeencapsulant. Further details of an example method that can be used toform the encapsulation cover 56 are provided in U.S. Pat. No. 9,172,929B2 to Mutschelknaus et al., entitled “ENCAPSULATION OF LIGHT-EMITTINGELEMENTS ON A DISPLAY MODULE,” and in U.S. application Ser. No.15/141,525 to Mutschelknaus et al., filed on Apr. 28, 2016, entitled“ENCAPSULATION OF LIGHT-EMITTING ELEMENTS ON A DISPLAY MODULE,” whichpublished as U.S. Published Application No. 2016/0247983 A1 on Aug. 25,2016, the disclosures of which are incorporated by reference as ifreproduced herein in their entireties.

As noted above, the geometry of the contrast mask 42 is selected so thatthe windows 46 allow the light emitted from the LEDs of the LED packages32 to pass outward (e.g., forward) from the display module 30 in orderto show the intended display image or video on the display surface ofthe display, but also so that the contrast mask 42 will maximizecoverage of the circuit board 34 in order to maximize contrastenhancement on the display module 30. The geometry that can achievethese goals may depend on the layout of the LEDs on the circuit board34. FIGS. 6 and 7 show an example LED package 60 mounted to an examplecircuit board 62. The LED package 60 and the circuit board 62 can beexamples of the LED packages 32 and the circuit board 34 that are usedin the display module 30 shown in FIGS. 3-5.

In the example shown best in FIG. 6, the LED package 60 comprising threeLEDs, in this example a first LED 64A (shown as a red LED 64A), a secondLED 64B (shown as a green LED 64B), and a third LED 64C (shown as a blueLED 64C), which will be collectively referred to as “LED 64” or “LEDs64” for brevity. The examples LEDs 64 are so-called “surface-mount” LEDs64, wherein at least a portion of a rear surface of the LED 64 issoldered directly to the circuit board 62. In some examples, a solderjoint (not shown) between the rear surface of the LED 64 and the circuitboard 62 also provides an electrical connection between the LED 64 and acorresponding connection pad 66A, 66B, 66C on the circuit board 62 (bestseen in FIG. 7). For example, the solder joints can provide anelectrical connection between the first LED 64A and a first connectionpad 66A, between the second LED 64B and a second connection pad 66B, andbetween the third LED 64C and a third connection pad 66C. In someinstances, the connection pads 66A, 66B, 66C will be referred tocollectively as the “connection pad 66” or “connection pads 66” forbrevity. Additional electrical connections to the LEDs 64 can beprovided via wires 68 or other conductors that electrical connect one ormore wire connection pads 70 on the LEDs 64 with one or morecorresponding wire connection pads 72 on the circuit board 62.

A contrast mask 80 is coupled directly the circuit board 62 (similar orsubstantially the same as described above with respect to the contrastmask 42 on the circuit board 34). Like the contrast mask 42 describedabove with respect to FIGS. 3-5, in some examples the contrast mask 80is molded onto at least a front surface 82 of the circuit board 62 andincludes a plurality of windows 84 (with only one window 84 being shownin FIG. 6 and with only a portion of two adjacent windows 84 shown inthe cross-sectional view of FIG. 7). Each window 84 provides an openingin the contrast mask 68 through which light from the LEDs 64 can beemitted, with each window 84 corresponding to one or more of the LEDpackages 60. The contrast mask 80 is also formed into one or morestructures that define the windows 84, such as one or more walls 96 thatsurround and define a window 84 (best seen in the cross-sectional viewof FIG. 7).

As is best seen in FIG. 6, the LEDs 64 of the LED package 60 arearranged in a specified pattern that is selected to provide for adesired emission of the light in order to produce the display image onthe display of which the display module is a part. In the example shownin FIGS. 6 and 7, the specified pattern of the LED package 60 is agenerally linear arrangement, with each of the LEDs 64 alignedsubstantially in the same direction (e.g., in a generally up-and-downarrangement with respect to the display surface and the display image).The sizing and shape of the windows 84 in the contrast mask 80 can beselected to accommodate the configuration of the LEDs 64, as well as toaccommodate the locations of the wire connection pads 72 located on thecircuit board 62 and to allow for placement and the securing of thewires 68 to the wire connection pads 70 and 72 within the space of thewindow 84.

As described above, the sizing and geometry of the windows 84 ispreferably selected so that the pixel pitch PP between the LED package60 and an adjacent LED package 60 is as small as possible, preferably 4mm or less, still more preferably 2.5 mm or less. For this reason, thoseof skill in the art will appreciate that the specific configuration ofthe components of the LED package 60 and the circuit board 62 can bemodified from that which is shown in FIGS. 6 and 7 in order to achieve adesired pixel pitch PP as well as to provide for a contrast mask 80 thatprovides for a desired contrast for the LEDs 64. For example, those ofskill in the art can envision modifying one or more of: the overallcross-sectional shape of the LED package 60, the general arrangement ofthe LEDs 64 with respect to one another on the LED package 60, or thepositioning of the wire connection pads 72 relative to the LED package60 and to specific LEDs 64. FIGS. 8A, 8B, and 8C show three examples ofdifferent configurations that have been contemplated by the inventors ofthe subject matter of the present disclosure. FIG. 8A shows a firstexample of an LED package 160 with LEDs 164A, 164B, and 164C that arearranged in a more bunched configuration, with the red LED 164A in atop-most position, the green LED 164B positioned below the red LED 164Aand aligned in a substantially vertical orientation, and with the blueLED 164C positioned laterally beside both the red and green LEDs 164A,164B and also aligned in a substantially vertical orientation. FIG. 8Aalso shows examples of wire connection pads 172 and their positionrelative to the various LEDs 164A, 164B, and 164C of the LED package160, with the LEDs 164A, 164B, and 164C being electrically connected tothe wire connection pads 172 with electrical conductors, such as wires68.

FIG. 8B shows a second example of an LED package 260 that is also in abunched configuration, but with the overall orientation of the LEDpackage 260 being in a generally horizontal orientation with the red LED264A one lateral side of the LED package 260 (e.g., a left-most side inFIG. 8B) and with the green LED 264B and the blue LED 264C positioned onthe other later side of the LED package 260 (e.g., the right-most sidein FIG. 8B) and with both the green and blue LEDs 264B and 264C beingaligned in a substantially vertical orientation. FIG. 8B also showsexamples of wire connection pads 272 and their position relative to thevarious LEDs 264A, 264B, and 264C of the LED package 260. Like the LEDpackage 160 of FIG. 8A, the LEDs 264A, 264B, and 264C of the LED package260 can be electrically connected to the wire connection pads 272 withelectrical conductors, such as wires 68.

FIG. 8C shows a third example of an LED package 360 that includes theLEDs arranged in an angled configuration, e.g., with each of the LEDs364A, 264B, and 364C being angled at a 45° angle relative to theorientation of the display module, with the red LED 364A on one lateralside of the LED package 360 (e.g., on the left side in FIG. 8C) and thegreen LED 364B and the blue LED 364C each being on an opposite lateralside of the LED package 360 (e.g., on the right side in FIG. 8C) andextending away from the red LED 364A at 45° with respect to the red LED364A and at 90° with respect to one another. FIG. 8C also shows examplesof wire connection pads 372 and their position relative to the variousLEDs 364A, 364B, and 364C of the LED package 360. Like the LED packages160 and 260 of FIGS. 8A and 8B, the LEDs 364A, 364B, and 364C of the LEDpackage 360 can be electrically connected to the wire connection pads372 with electrical conductors, such as wires 68.

FIGS. 8A-8C each also show an outline 85 representing the outer borderof the window formed by a contrast mask (e.g., of the window 84 in thecontrast mask 80 in the example of FIGS. 6 and 7). The outline 85 showsthe position of the LED packages 160, 260, 360 within the window of thecontrast mask as well as what portions of the wire connection pads 172,272, and 372 would be exposed by the windows (e.g., that are not coveredby the contrast mask) and therefore would be available for a weldingdevice to connect the wires 68 between the LED packages 160, 260, 360and the wire connection pads 172, 272, 372.

The configurations of the LED packages 60, 160, 260, and 360 and of thewire connection pads 72, 172, 272, 372 shown in FIGS. 6, 7, 8A, 8B, and8C are intended only to provide examples so that the person of ordinaryskill in the art will be able to understand the concepts of theinventions disclosed herein. Those of skill in the art will appreciatethat the configurations shown in FIGS. 6, 7, 8A, 8B, and 8C are merelyintended as examples, and not as a limiting or exhaustive list of thepotential configurations that could be used for the LEDs, wireconnection pads, or the LED packages. Similarly, those of skill in theart will appreciate that the orientations of the LED packages shown inFIGS. 6, 8A, 8B, and 8C (e.g., generally vertical, generally horizontal,or generally at a 45° angle relative to horizontal and vertical) are notlimiting, and those of skill in the art will be able to contemplaterotating any of the configurations of any individual component or groupsof components at any angle relative to that which is shown in FIGS. 6,8A, 8B, and 8C without varying from the scope of the present disclosure.

The above detailed description includes references to the accompanyingdrawings, which form a part of the detailed description. The drawingsshow, by way of illustration, specific embodiments in which theinvention can be practiced. These embodiments are also referred toherein as “examples.” Such examples can include elements in addition tothose shown or described. However, the present inventors alsocontemplate examples in which only those elements shown or described areprovided. Moreover, the present inventors also contemplate examplesusing any combination or permutation of those elements shown ordescribed (or one or more aspects thereof), either with respect to aparticular example (or one or more aspects thereof), or with respect toother examples (or one or more aspects thereof) shown or describedherein.

In the event of inconsistent usages between this document and anydocuments so incorporated by reference, the usage in this documentcontrols.

The above description is intended to be illustrative, and notrestrictive. For example, the above-described examples (or one or moreaspects thereof) may be used in combination with each other. Otherembodiments can be used, such as by one of ordinary skill in the artupon reviewing the above description. The Abstract is provided to complywith 37 C.F.R. § 1.72(b), to allow the reader to quickly ascertain thenature of the technical disclosure. It is submitted with theunderstanding that it will not be used to interpret or limit the scopeor meaning of the claims. Also, in the above Detailed Description,various features may be grouped together to streamline the disclosure.This should not be interpreted as intending that an unclaimed disclosedfeature is essential to any claim. Rather, inventive subject matter maylie in less than all features of a particular disclosed embodiment.Thus, the following claims are hereby incorporated into the DetailedDescription as examples or embodiments, with each claim standing on itsown as a separate embodiment, and it is contemplated that suchembodiments can be combined with each other in various combinations orpermutations. The scope of the invention should be determined withreference to the appended claims, along with the full scope ofequivalents to which such claims are entitled.

What is claimed is:
 1. A display module comprising: a circuit board; aplurality of light-emitting elements coupled to a front surface of thecircuit board, wherein the plurality of light-emitting elements isarranged in an array configured to produce at least a portion of adisplay image at the front surface of the circuit board; and a contrastmask directly coupled to the front surface of the circuit board, thecontrast mask defining a plurality of windows, with each windowsurrounding a group of one or more of the plurality of light-emittingelements.
 2. The display module of claim 1, wherein the contrast mask ismolded onto the front surface of the circuit board.
 3. The displaymodule of claim 1, wherein each group of one or more of the plurality oflight-emitting elements comprises a pixel of two or more of thelight-emitting elements, wherein a plurality of the pixels is arrangedto provide the array.
 4. The display module of claim 3, wherein thecontrast mask reduces occurrence of a halo effect around one or more ofthe pixels.
 5. The display module of claim 3, wherein adjacent pixels ofthe plurality of pixels are spaced apart by a specified pixel pitch. 6.The display module of claim 5, wherein the specified pixel pitch is nolarger than 4 millimeters.
 7. The display module of claim 5, wherein thespecified pixel pitch is no larger than 2.5 millimeters.
 8. The displaymodule of claim 1, wherein the contrast mask enhances contrast betweenlight being emitted by the light-emitting elements and an appearance ofdark or black in the display image.
 9. The display module of claim 1,wherein the contrast mask is formed from a moldable material.
 10. Thedisplay module of claim 1, wherein the contrast mask is formed from atleast one of: an epoxy-based material, a silicone-based compound, or ablack carbon compound.
 11. A method comprising: providing or receiving acircuit board; molding a moldable material onto at least a portion of afront surface of the circuit board to form a contrast mask; and mountinga plurality of light-emitting elements onto the front surface of thecircuit board in an array configured to produce at least a portion of adisplay image at the front surface of the circuit board; wherein themolding of the moldable material comprises forming a plurality ofwindows in or through the contrast mask to allow for emission of lightfrom the light-emitting elements to produce a display image at the frontsurface of the circuit board, wherein each window surrounds a group ofone or more of the plurality of light-emitting elements.
 12. The methodof claim 11, wherein each group of one or more of the plurality oflight-emitting elements comprises a pixel of two or more of thelight-emitting elements, wherein a plurality of the pixels is arrangedto provide the array.
 13. The method of claim 12, wherein the mountingof the plurality of light-emitting elements comprising mounting adjacentpixels of the plurality of pixels so that the adjacent pixels are spacedapart by a specified pixel pitch.
 14. The method of claim 13, whereinthe specified pixel pitch is no larger than 4 millimeters.
 15. Themethod of claim 13, wherein the specified pixel pitch is no larger than2.5 millimeters.
 16. The method of claim 12, wherein the contrast maskreduces occurrence of a halo effect around one or more of the pixels.17. The method of claim 12, wherein the contrast mask enhances contrastbetween light being emitted by the light-emitting elements and anappearance of dark or black in the display image.
 18. The method ofclaim 11, wherein the step of molding the moldable material onto atleast a portion of the front surface of the circuit board precedes thestep of mounting the plurality of light-emitting elements onto the frontsurface of the circuit board.
 19. The method of claim 11, wherein thestep of mounting the plurality of light-emitting elements onto the frontsurface of the circuit board precedes the step of molding the moldablematerial onto at least a portion of the front surface of the circuitboard.
 20. The method of claim 11, wherein the moldable materialcomprises at least one of: an epoxy-based material, a silicone-basedcompound, or a black carbon compound.